The contamination of soil and groundwater by such compounds as chlorinated solvents, n-nitrosodimethylamine (NDMA), nitrates and other explosive compounds poses serious environmental problems. Present in wastewater as a result of a variety of industrial methods, these hazardous compounds pose health risks as they can readily leach into drinking water sources, in addition to polluting soil and groundwater.
Over the years, many methods have been developed in order to decontaminate polluted soil and wastewater, some involving in situ methods and others that involve ex situ methods. For example, zero valent iron (ZVI) and metal catalysts have been used to remove contaminants through reduction reactions. The use of iron for decontamination is inhibited as the iron corrodes. In some instances, catalytic methods require high operating temperatures and pressures, or are pH dependent, in order to effectuate decontamination.
In addition to catalytic reduction, various biological and abiotic methods for ex situ and in situ remediation of contaminated soil and groundwater have been developed. Methods including air stripping, photolysis using ultraviolet light, advanced oxidation, activated carbon adsorption and removal of contaminant precursors have also been used. However, many of these treatment methods are either not economical or result in undesirable secondary waste streams. Traditional treatment methods also often require days or even months to achieve the desired decontamination levels.
Therefore, there is still a need for an improved method and system for treating contaminated soil and waters.